Roof or floor construction



Jan. 26 1926.

H. E. MARKS or on FLOOR CONSTRUCTION Filed April 16, 1923 hib/111111111111121 WITNESSESS in the trade being Patented Jan. 26, 1926,4

UNITED STATES HERBERT E. Manns, or sEwIcxLEY, rnNNsnvANu.

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Application med April 16, 1923. serial No. 632,243.

To all whom t may concern.'

` Be it known that I, HERBERT E. MARKS, a citizen of the United States, and a resident of Sewickley, in the county of Allegheny and State of Pennsylvania, have invented a new andl useful Improvement in Roof or Floor Constructions, of which the following is a specification.

This invention relates to roof structures and is in particularan improvement on Vthe lroof structure shown in my Patent No. 1,398,079, issued November 22, 1921. The object of the invention is to improve roof structures of the kind illustrated in the above named patent'so that the reinforcing metal mesh is located as low down' in they slab as possible, without the necessity of having the mesh sheet sag downwardly be- .being taken parallel to the main supporting beams or purlins; Fig. 2 is a similar section taken at right angles to the section of Fig.

1; and Fig. 3 is a detail view of one of the notched bars.

The invention is applicable to a roof of any type and in the drawings, for simplicity, is shown as applied to a flat roof. In,said drawings 2 indicates the main frame members, in this instance the purlins. These are shown as formed by rolled channel beams, but obviously structural shapes ofiany suitable kind can be used. Supportedupon the purlins are a plurality of angle bars, specifically of the kind shown as T-bars, 3, which rest with their base flanges upon the purlins and are suitably secured thereto and with their legs projecting upwardly. These T-bars extend parallel to each other and are spaced sufliciently 'close that the distance therebetween can be bridged by ordinary sizes of commercial plaster or gypsum boards. The latter are well Iknown articles enerally composed o molded gypsum or t e like, and generally are quite* thin, usually about three-eighths of an inch in thickness. The plaster or4 gypsum boards are shown at 4.; The can be chosen of any suitable len h, and ln use form the centering upon whlch the cementitious roof composition is poured, thus dispensing with the usual centering or false` work. Since the laster boards are quite Y thin it is desrab e to support their end y portions to prevent them from saggin when v into the` cementltiousf material is pour place. As a means-for Supporting their end portions it is preferred to use small angle members 6, also shown as T-bars and Aof a length equal to the distance betwen the adjacent main T-bars 3 and having their ends `resting upon the flanges of the latter. Confor the metallic reinforcement, 7 preferably a metallic mesh, such as metallic lath, wire mesh or the like. As shown in my previous patent, the metallic mesh rests upon the top edges of the upstanding flanges of the T- bars 6. After. the mesh is put in place, cementitious material, such as concrete, gypsum Ior other suitable material, mixed with a proper proportion of water, is-poured directly in place, that is, upon the centering formed by the plaster boards 4 and to a depth somewhat greater than the main T- \bars,3. This composition is of such a nature that when poured in' place it bonds onto theplaster boards so that the latter and the solidifiedy cementitious material form a unitary or monolithic slab with the reinforcement embedded in it. Because the plaster boards form a part of the slab, the reinforcing metallic mesh when resting4 on the tops of the flanges vof the small T-bars 6.will be spaced ag considerable distance above the lower tension zone of the complete slab, unless said meshis 'caused to sag or hammock between the points ofits supsible, and without the necessity of it sag-4 ging down, and therefore remaining straight and more effectively taking care of the tension stresses, I provide the upstanding flanges of the small T-bars 6 with notches 8 of such depth as the metallicmesh is intended to assume, and spaced such distances f apart as to register with the longitudinal strands of the metal mesh. When the metallic mesh is thus put in place it will be straight from end to vend of the panel but nevertheless will be positioned so low down that after the cementitious material is 4 insure that said mesh will not be exposed on the lower face of the slab.

The metallic mesh lmay be a Vcontinuous stri extending from edge to edge of the roo in the case of a flat roof, or :from the eaves to the ridge, in the case of a sloping roof, or it may be composed of a number of pieces the ends of which are overlapped such a distance that when embedded in the cementitious material it has the same reinforcing eli'ect as a continuous strip. As shown in the drawings the strip of metallic mesh is of a width to fit between adjacent main T- bars 3, but if desired it-can be made considerably wider so as to overlap atits edges the upper edges of the T-bars 3 and alsoupstanding angles back to back, will serve the s ame purpose.

With this constructlon and since the cementitious material is poured to a depth somewhat greater'than that vof the T-bars 3, the entire roof becomes in effect a monolithic lslab with no portion of the metal exposed on the top surface and no portion of the reinforcing mesh exposed on the bottom surface. Such slab is strong and can be of minimum thickness and the metal members can be of light cross section. VThe plaster boards used in the waydescribed servev as centering 'thus dispensing with the usual centering or false work and result in a great saving in cost of erection. Such plaster boards also give a good finish to the lower face of the roof which forms 'the ceiling of the room underneath, and also prevents such ceiling from dusting, that is from small bits of cementitious material spalling volf and falling down into the room below.

The top surface of this roof structure will be suitably water-proofed, such as applying thereto a coating of asphaltum or the like,

and can be finished in any of the ways of inishing roofs of this kind, such Yas by providing the same with a `gravel or-other surface.

I claim:

l. `A roof of the character described, comprising purlins, metal angle members s upported on the'purlins and presenting oppositely projecting iianges, small angle members having substantially straight longitudmal axes extending between the'first named angle members and resting on. the iianges members entering the notches in the second named angle members and supported by the latter in closely spaced relation to the composition boards,` and cementitious materialv -embedded .in all of said metallicA members and bonded to said composition boards.

2, A- structure of the character described comprising parallel angle members presenting oppositely projecting flanges, small metal angle members having substantially straight longitudinal axes extending between the `first named 'angle members and resting on the flanges of the latter and also presenting oppositely projecting flangesand an upstanding flange provided with vspaced notches, the bottoms of which lie in a plane closely adjacent to that of the base portions 'of the said small angle members, plaster boards bridging the'space between angle members, lmetal 'mesh placed with its longitudinal members in the notches of the small' angle members and held by the 'latter in closely spaced relation to the plaster boards, and a cementitious body molded in place on the plaster boards and bonding therewith and extending above fthe first named angle members and thereby forming a monolithic-reinforced slab.

In testimony whereof, I sign my name..

HERBERT E. MARK S, 

